Fuel injection system



G. M. HOLLEY, JR

FUEL INJECTION SYSTEM June 16, 1959 2 Sheets-Sheet 1 Filed Oct. 15, 1956 INVENTOR. .GEO RGE M.HOLLEY JR.

ATTORNEYS June 16, 1959 GJM. HOLLEY, JR

FUEL INJECTION SYSTEM 2 Sheets-Sheet 2 Filed Oct. 15, 1956 02 I. mm

INIVENTOR.

GEORGE M.HOLLEY JR.

ATTORNEYS Unite.

2,890,691 FUEL 1NJECTION SYSTEM Application October 15, 1956, Serial No. 615,931

16 Claims. (Cl. 123-140) The present invention relates to a fuel injection system.

It is an object of the present invention to provide a fuel injection system in which metered charges of fuel are injected under pressure into the cylinders of an internal combustion engine and in which the quantity of fuel in the metered charges is controlled by variably limiting the maximum capacity of the pumping cylinders.

More specifically, it is an object of the present inven tion to provide a fuel injection system comprising a pumping chamber of variable capacity, an inlet passage for supplying fuel to the chamber, an engine operated valve in said passage, a pressure loaded outlet passage connecting said chamber to a cylinder of the engine, adjustable means for limiting the increase in capacity of said pumping chamber, and positive means for reducing the capacity of said chamber while said valve is closed to force fuel from said pumping chamber through said pressure loaded outlet passage to the cylinder of said engine.

It is a further object of the present invention to provide a fuel injection system as described in the preceding paragraph in which the means for limiting the increase in capacity of said pumping chamber is controlled by an operating condition of the engine and more particularly, by a subatmospheric pressure variable in accordance with manifold vacuum.

. It is a further object of the present invention to provide a fuel injection system comprising means -for injecting metered charges of fuel into the cylinders of an internal combustion engine provided with a throttle controlled air manifold, in which the quantity of fuel in said metered charges is regulated in accordance with manifold vacuum.

It is a further object of the present invention to provide in the fuel injection system as described in the preceding paragraph, means for increasing the quantity of fuel in the metered charges under cold starting conditions until the engine starts and thereafter, for reducing the quantity of fuel in the metered charges to the quantity as dictated by the source of sub-atmospheric pressure.

It is a further object of the present invention to provide in a fuel injection system as described in either of the two preceding paragraphs, means responsive jointly to engine temperature and manifold vacuum for regulating the quantity of fuel in the metered charges to increase the quantity of fuel when the engine is cold to produce a fast idle condition.

Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying drawings, illustrating preferred embodiments of the invention, wherein:

States Patent Figure 1 is a diagrammatic view of a simplified form of the fuel injection system.

Figure 2 is a diagrammatic view of the system shown in Figure 1 with cold start and fast idle mechanism associated therewith.

Figure 3 is a vertical sectional view through a practical embodiment of the fuel injection system diagrammatically illustrated in Figure 1.

Figure 4 is a fragmentary vertical sectional view similar to Figure 3, taken in a different radial plane.

Figure 5 is a fragmentary vertical sectional view showing actuation of the thermostat by hot air.

Referring first to Figure 1, there is disclosed a fuell injection system for an internal combustion engine which: includes a drive shaft 10 adapted to be connected to a: rotating part of the engine so as to be driven at a speed.

dependent upon engine speed. Connected to the upper end of the shaft 10 as by the pin 12 is a distributing: valve 14 rotatable in a chamber 16 provided in a sleeve; 17 having a plurality of circumferentially arranged passages 18 each of which communicates with a passage in-- dicated generally at 20. The passage 20 comprises an: inlet portion 20a leading to a pumping chamber or cylin-- der 22, and an outlet portion 2% leading to a cylinder of the internal combustion engine. The outlet portion 20b of the passage is provided with a pressure loading valve indicated generally at 24 associated with a suitable nozzle for injecting the fuel into the cylinder in desired condition.

The distributing valve 14 has a radial passage 26 therein which communicates serially with the passages 18 in the sleeve 17. The inner end of the radial passage 26 is in communication with the interior of the chamber 16 to which fuel is supplied under substantial pressure through a passage 28.

Each of the passages 20 communicates with a pumping chamber or cylinder 22 and each of these cylinders is provided with a piston 30 movable therein. During the interval in which the passage 18 is in communication with the passage 20, fuel under substantial pressure flows into the passage 20. The pressure of fuel at this time:

however, is insufiicient to open the pressure loading valve.

24 and accordingly the fuel moves the piston 30 down-- wardly and fills the portion of the cylinder 22 above the: piston. It will of course be appreciated that the passages: 18 includecircumferentially elongated outlet portions so that they remain in communication with the passage 20 for an interval sufficient to fully charge the passage 20b discharged from each cylinder 22 during a pumping stroke of the piston 30 therein. This means comprises a plate 42 mounted for vertical movement and having a plurality of openings 44 disposed between the lower ends of the pistons 30 and the upper ends of the extensions 40. The arrangement, as clearly illustrated in Figure 1, is such that upon upward movement of the plunger 38 caused by passage of the cam portion 34 therebelow, the reduced extension 40 engages the lower end of the piston 30 and positively moves it upwardly. This is of course timed so that during upward movement of the piston 30, the passage 18 of the valve 14 is out of registration with the passage 20 so that the positive upward movement of the piston 30 results in positive injection of fuel into the cylinder at a pressure determined by the setting of the pressure loading valve 24. It will be observed that downward movement of the piston 30 as fuel flows into the passage 20 is terminated byits engagement with the upper. surface of the plate 42. Accordingly, adjustment of. the plate 42-vertically results inan adjustment or regulationof. the quantity of fuel, received in the cylinder 22 and injected into the cylinder of the engine during the next stroke of the piston; In. accordance With the present invention there is provided means responsive to a condition of the engine for regulating the position of the metering plate 42; This means comprises a sealed chamber. 46having a movable wall 48 illustrated as a flexible diaphragm. The interior of the chamber 46 isv connected to a source of sub-atmospheric pressure which is dependent upon mam.- fold vacuum by suitable passage means, a portion of which is indicated at 50. The outer surface of the flexible diaphragm 48 is subjected to atmospheric pressure and at the interior of the chamber there is provided a compression spring 52 urging the diaphragm 48 outwardly. Carried by the flexible diaphragm 48 is a post 54 connected to one end of a lever 56 which is pivoted intermediate its ends as indicated at 58. The opposite. end of the lever is connected at 60 to alink 62, the opposite end of which is pivotally connected as indicated: at 64 to a cam 66. The cam 66 is provided with a stationary pivot 68 and engages a cam follower or roller 70 carried by a lever arm 72. The lever arm 72 is provided. with a fixed pivot 75 and at its end opposite to the roller 70 is provided with a roller 76 engaging the underside of the metering plate 42. In practice of course, the lever 72 is preferably bifurcated and a pair of rollers such as 76 are provided which engage the undersideof the metering plate 42 at diametrically opposite points.

With the foregoing construction it will be observed that the quantity of fuel injected into each engine cylinder at each upward stroke of the associated piston 30 is determined by the location of the metering plate 42 which in turnis positioned in accordance with an engine condition. In the embodiment of the invention illustrated in Figure 1, the passage means 50 may communicate directly with the engine manifold. Accordingly, the quantity of fuel delivered to the engine is determinedby mani fold pressure or vacuum and by engine speed. At constant manifold pressure, it will of course be apparent that the total fuel flow is increased in proportion to speed as the number of pumping strokes is increased, while the length of the stroke remains constant.

Referring now to Figure 2 there is. illustrated a sysdescribed. In addition, the underside of the piston88 is subjected to this sub-atmospheric pressure through ports 90 provided in the wall 82, thus establishing a force tending to move the piston 88 downwardly until its lower end contacts the upper surface of the wall 82. Located within the cylinder 86 and extending between the wall 82 and the piston 88 is a bi-metallic spring 92 adapted when cold to expand, as for example to the position illustrated in the figure. The strength of the bimetallic spring 92 is such that in the absence of pressure differential on opposite sides of the piston 88, it is effective when cold to elevate the piston 88 as shown with a force suflicient to operate through the cam 66 to position the metering plate 42 downwardly so as to 1 iseffective only to increase the quantity of fuel in the charges to provide a rich mixture for starting.

The source of sub-atmospheric pressure applied to the interior of the chamber 80 is indicated at the left in Figure 2 where there is illustrated an air induction passage 94'having a throttle plate 96 mounted therein. The

tem similar to that diagrammatically illustrated in Fig I ure 1, to which certain refinements have been added. Insofar as the system shown in Figure 2 is the same as shown in Figure 1, like reference numerals have been applied, butthe elements of the system willnotbe fur? ther described.

In the fuel injection system illustrated in Figure 2 the adjustment of the metering plate 42 is accomplished by mechanism which includes a chamber 80having a movable wall 82. connected to an annular flexible diaphragm 84. Mounted on the movable wall82 is cold start-mechanism which includes an upwardly extending cylinder 86 in which is. movably mounted. a piston 88. The upper sideof the piston 88, aswell as the upper side of the wall; 82 and flexible diaphragm 84, is .sub.-. jected to atmospheric pressure, The interior of the chamber 80, and.hence the underside of the Wallis-2 and flexible diaphragm 84, is subjectedtoa below atmospheric; pressure. which is dependent upon anengine condition or engine conditions as will subsequently be air induction passage is intended for downward flow of air as indicated by the arrow and the portion of the passage below the throttle 96 connects to an air distribution manifold. The sub-atmospheric pressure resultingfrom flow of air past the restriction of the throttle plate, commonly referred to as manifold vacuum, is thus available in the passage 94 below the throttle plate 96.

A passage 98 provided with a restriction 100 connectsv to the passage 94 below the throttle plate 96 and leads through passage means indicated diagrammatically at 102 to the interior of the chamber 80. If unmodified this passage would provide the interior of the chamber and the interior of the cylinder 86 with sub-atmospheric pressure equal to manifold vacuum. However, means are provided for insuring sufliciently rapid idle operation of the engine while it is cold to prevent stalling. This means comprises a chamber 104 connected through a passage 106 to the air induction passage 94 at a point downstream from the throttle plate 96, and also connected through a passage 108 with the air induction passage 94 at a point upstream from the throttle plate 96. A restriction 110 is provided between the passage 108 and the chamber 104 and this restriction includes a port closed by a valve element 112 carried by a thermally responsive member 114 located in a chamber 116. The chamber 116 communicates by a passage means 118 withmeans forv subjecting the thermally responsive member 114 to engine temperature. The thermally responsive member 114 may be actuated by oil temperature, water tempera-. ture, exhaust heat, or air as desired. In Figure 2 connection of the chamber 116.to hot water from the engine cooling system is shown. Passage means 118 connects chamber 116 for a circulation of hot water induced by the pump 119, which circulates water between the radia tor 120 and-the engine block 121. As shown in Figure 5, thermostat 114 is connected to respond to the temperature of exhaust gases. Here air passes through a stove 122 placed in exhaust manifold 123 to be heated by exhaust gases. Circulation of heated air through the chamber 116 is induced by a connection to the intake manifold 124 as illustrated. In any case, it will be observed that the value of sub-atmospheric pressure prevailing in chamber 104 will be increased by the bleeding;

The chamber 104 communicateswith.

value of sub-atmospheric pressure communicated through passage 98 to the interior of the chamber 80 will he in creased so long as air is bled into the chamber 104 through the passage 108. When however, the valve 112 closes, as it does when the engine reaches normal operating conditions, the pressure transmitted to the interior of the chamber 80 through the passage 98, 102 is substantially equal to manifold vacuum and thereafter, metering of the charges of fuel injected by the strokes of the pistons 30 is dependent on engine manifold vacuum.

Accordingly, it will be observed that in Figure 2 means are provided for regulating the supply of air to the fuel injected internal combustion engine and means responsive generally to air flow are provided for regulating the quantity of fuel delivered to the engine to provide a rich mixture for starting, for providing an increase in fuel supply to produce fast idling during the warm up period, and for thereafter regulating the fuel supply in accordance with manifold vacuum.

Referring now to Figures 3 and 4 there is illustrated a practical embodiment of the invention diagrammatically illustrated in Figure 1. In these figures the structure comprises a body 130 open at its interior as indicated at 132 and closed at its upper end by an annular disc 134 having axially extending openings 136 for receiving bushings 138 which carry the pistons 140. The drive shaft 142 has keyed or otherwise secured thereto the cam plate 144 carrying the cam 146 for operating the pistons 140. Metering plate 148 is vertically movable on the stationary sleeve 150 and is provided with openings for the passage of the upper reduced ends of the actuating plungers 152. The plungers 152 are urged downwardly by compression springs 154 and the lower ends of the plungers are received in cup-shaped members 156 which bear against the upper surface of the cam plate 144.

The position of the metering plate 148 is determined by the lever 158 which in turn is actuated by a cam lever 160 connected by link 162 to lever 164.

Accurately located on top of the body 130 is the annular distributing disc 166 including a plurality of radially extending passages 168 communicating with passages 170 formed in a sleeve 172. Rotatable within the interior of the sleeve 172 is the valve 174 which is keyed or otherwise secured to the upper end of the drive shaft 142. Each of the passages 168 is in communication with a cylinder 176 which receives the upper end of the pumping piston 140.

The valve 174 is provided with one, or in some cases aplurality of radially extending passages 178 adapted to register sequentially with the annular array of passages 170 and thus to supply fuel sequentially to the pumps formed by the cylinders 176 and the pistons 140.

As best seen in Figure 4, fuel is supplied through a tapped opening 180, passage 182, annular groove 184, and radial passage or passages 186 to the interior of the valve 174.

Secured to the top of the disc 166 is a chamber 188 comprising a lower atmular member 190 and an upper annular member 192 between the peripheries of which is clamped the outer edge of a flexible diaphragm 194. The diaphragm 194 carries a central plate 196 having an up wardly extending cylindrical portion 198 terminating in a post 200. The upper annular member 192 is flanged as indicated at 202 and carries an adjustable spring abutment 204 engaged by a compression spring 206, the lower end of which engages the upper surface of the plate 196. Located within the cylindrical upward extension 198 is a compression spring 208 the lower end of which is received in a recessed seat 210 provided at the upper surface of the lower annular member 190. It will be observed that springs 206 and 208 provide a resultant force biasing the plate 196 upwardly against the atmospheric pressure which exists above the plate. The value of the resultant spring force can of course be adjusted by adjustmentof the abutment 204. The lever l64 is provided with a stationary pivot 212 and is pivotally connected as indicated at 214 to the post 200. Theinterior of the chamber 188 provided beneath the movable wall 196 is connected by suitable conduit means (not. shown) to a source of sub-atmospheric pressure dependent upon an engine operating condition and preferably to a source of manifold vacuuui either directly, or as modified by' the fast idle adjustment means diagrammatically illus' trated Figure 2. It will 'of course also be evident that instead of connecting the lever 164 directly to the movable plate 196 of the chamber 188, the cold start mechanism diagrammatically illustrated in Figure 2 may beapplied.

The drawings and the foregoing specification constitute a description of the improved fuel injection system in such full, clear, concise and exact terms as to enable any person skilled in the art to practice the invention, the scope of which is indicated by the appended claims.

What I claim as my invention is:

1. A fuel injection system for an internal combustion engine comprising a source of fuel under pressure, a variable volume pumping chamber connected to receive fuel from said source, said chamber being substantially freely expansible to receive such fuel, adjustable means for limiting the expansion of said chamber to meter the quantity of fuel received therein, a pressure loaded discharge passage connected to said chamber, and positive acting means operable in accordance with engine speed for expelling the metered quantity of fuel from said chamber.

2. A fuel injection system for an internal combustion engine comprising a source of fuel under pressure, a variable volume pumping chamber connected to receive fuel from said source, said chamber being substantially freely expansible to receive such fuel, adjustable means responsive to engine manifold vacuum and temperature for limiting the expansion of said chamber to meter the quantity of fuel received therein, a pressure loaded discharge passage connected to said chamber, and positive acting means operable in accordance with engine speed for expelling the metered quantity of fuel from said chamber.

3. A fuel injection system for an internal combustion engine comprising a source of fuel under pressure, a variable volume pumping chamber connected to receive fuel from said source, said chamber being substantially freely expansible to receive such fuel, adjustable means responsive to engine manifold vacuum for limiting the expansion of said chamber to meter the quantity of fuel received therein, a pressure loaded discharge passage connected to said chamber, and positive acting means operable in accordance with engine speed for expelling the metered quantity of fuel from said chamber.

4. A fuel injection system for an internal combustion engine comprising a source of fuel under pressure, a variable volume pumping chamber connected to receive fuel from said source, said chamber being substantially freely der connected to receive fuel from said source, a piston movable in said cylinder to accommodate inflow of fuel into said cylinder, a pressure loaded discharge passage connected to said cylinder, valve means operable in timed relation to the engine to close the connection between said cylinder and said source, adjustable means to limit movement of the piston in the cylinder during inflow of fuel to meter the charge of fuel therein, and cam means operable in timed relation to engine speed for positively moving said piston while said valve means is closed to expel the metered'charge of fuel from said piston through said discharge passage.

6. A fuel injection system for an internal combustion engine comprising a source of fuel under pressure, a cylinder connected to receive fuel from said source, apiston movable in said cylinder to accommodate inflow of fuel into said cylinder, a pressure loaded discharge passage connected to said cylinder, valve means operable in timedrelation to the engine to close the connection between rsaid cylinder. and said' source, adjustable means responsive to engine manifold vacuum and temperature to limit movement of the pistonin the cylinder during inflow of fuel to meter the charge of fuel therein, and cam means operable in timed relation to engine speed for positively moving said piston while said valve means is closed to expel the metered charge of fuel from-said piston through said discharge passage.

7. A fuel injection system for an internal combustion engine comprising a source of fuel under pressure, 2. cylinder connected to receive fuel from said source, a piston movable in said cylinder to accommodate inflow of fuel into said cylinder, a pressure loaded discharge passage connected to said cylinder, valve means operable in timed relation to the engine to close the connection between said cylinder and said source, adjustable means responsive to manifold vacuum to limitmovement of the piston in the cylinder during inflow of fuel to meter the charge of fuel therein, and cam means operable in timed'relation to engine speed for positively moving said piston while saidvalve means is.closed to expel the metered charge of fuel fromsaid piston through said discharge passage.

8. A fuel injection system for an internal combustion engine comprising abody having a plurality ofpumping cylinders therein, a, source of fuel. under-pressure, inlet passages connecting said source to, all of said cylinders, engine driven valve means in said passages opening and closing said inlet passages in a repeating sequence, outlet passages connected to each of saidcylindcrs, pressure loaded outlet valves in said outlet passages, pistons movable in said cylinders byinflow of fuel into said cylinders, adjustable means limiting movement of said pistons iupon inflow. of fuelto meter the-charges of fuel therein, and engine driven cam means for moving said pistons .while the associated valve means is-closed in a pumping-stroke to-expel the-metered-charges from the cylinders.

9. Asystem as defined inclaim 8 in which an engine drivenshaft is received in said'body, said cylinders are disposed around said shaft, andlsaid engine driven valve means comprises a valve member carried by saidshaft and'having a port sequentially in registrationwith the inlet passages to said cylinders.

10. Asystem as defined in claim 8 in whichan-engine driven shaftis received insaid body, saidcylinders are disposedaround said shaft, and said engine driven cam means is carriedby said shaft.

11. A system as defined in claim 8 in which an enginetioned in accordance with manifoldpressure, actuating.

mechanism connecting said movable wall andsaid meteringmeans said, actuating means comprising means responsivejointly to manifold vacuum andambient temperature to modify the action of said adjusting means while 13. In a fuel injection systemfor an internalcombustion engine having-a throttle controlled air intake mani fold, means for injecting fuel into said engine, adjustable metering means for regulating the rate offuel injection, a chamber having a movable wall exposed atits outer side to atmospheric pressure, a firstrestrictedpas sage connectingthe interior of said chamber to theengine manifold, an auxiliary passage having a valved restriction therein connected atone end to-said first passage between the restriction therein and said chamber and connected at the other end to a source of airsubstantially at atmospheric pressure, valve means responsive, to engine temperature to open said auxiliary passage while said-engine is cold to produce fast idling, and actuatingmechanismconnecting said movable wall and said metering means.

14. In a-fuel injection system for an internal combus: tion engine having a throttle controlled airv intake manie fold, means for injecting fuel into said engine, adjustable metering means for regulating the rate of fuelinjection, a chamber having a movable wall exposed at its outer side to atmospheric pressure, a first restricted passage connectingthe interior of said chamber tothe engine manifold, an auxiliarypassage having-a valved restriction therein'connected at one end to said first passage between! the restriction therein and said chamber and'connected at: the other end to-a source of air substantially at atmospheric, pressure, valve means responsive, to-engine temperature ,to open said auxiliary passage while said engine is;cold to produce fast idling, actuating mechanismcona necting said movable wall and said meteringmeans, and; a cold start device connected between said movable wall and-said actuating mechanism comprising means responsive jcintly to ambient temperature and manifoldvacu um and'operable under cold start: conditions to increase the rate of'fuel injection until the engine starts.

15. In a fuel injection system for an internal combustion engine having a throttle controlled air. intake manifold, means for injecting fuel intosaid engine,.adjustable metering means for regulating the rate ofi fuel injection, a chamber having a movable wall exposed at its outer side to atmospheric pressure, a first restricted passage connecting the interior of said chamberto-the engine manifold, an auxiliary passage having a valved restriction therein connected at one end to said first passage between the restriction therein and said chamber and'connected at the other end to a source of air-sub.- stantially atatmospheric pressure, valve means respon-- sive to engine temperature to open said auxiliary passage while said engine is cold to produce fast idling, actuating mechanism connecting said movable wall and said metering means, acold start device connected betweensaidmovable wall and saidactuating mechanism comprising a collapsible sealed structure, means connecting-the interiorofsaid structure to engine manifold vacuum, yieldable expansible temperature responsive means .within; said structure urging itto expanded condition undercold' start conditions, said'temperature responsive means be! ing operable under cold start conditions to increase the. rate of: fuel injection until the engine starts and being. yieldable as a resultof manifold vacuum'when the engine starts to-reduce the quantity of.fuel;to that dictated-by: manifold vacuum and'engine temperature.

16. In-a fuel injection system for an'internal-combustion engine having a throttle controlled air intake'manifold, means for injectingfuel into said engine, adjustable:

metering means forregulating the rate offuelinjection,

I means including a member variably positioned in accordance with manifold pressure, actuating mechanism connecting said member and said metering means, said actuating mechanism including a hollow collapsible device having its interior in communication with a source of manifold vacuum, a temperature responsive element in 5 said device responsive to ambient temperature and in the absence of a vacuum within said device at least as great as that prevailing upon starting of the engine being efiective to expand said device to provide extra fuel during cold starting and to reduce the fuel flow immediately 10 upon starting of the engine.

References Cited in the file of this patent UNITED STATES PATENTS Summers Jan. 21, 1947 Wallace Apr. 13, 1948 Beardsley Aug. 17, 1948 Isreeli et a1. Oct. 11, 1955 Aldinger Jan. 15, 1957 FOREIGN PATENTS Great Britain May 1, 1946 

